Sinopestalotiollides A–D, cytotoxic diphenyl ether derivatives from plant endophytic fungus Pestalotiopsis palmarum

Four new diphenyl ether derivatives, sinopestalotiollides A–D (1–4), one new natural α-pyrone product (11), as well as twelve known compounds (5–1 7), were obtained from the ethyl acetate extract of the endophytic fungus Pestalotiopsis palmarum isolated from the leaves of medicinal plant Sinomenium acutum (Thunb.) Rehd et Wils. The structures were elucidated by HR-ESI-MS and NMR spectrometry data. Bioassay experiments revealed that compounds 1–4 and 11 exhibited strong to weak cytotoxicities against three human tumor cell lines Hela, HCT116 and A549.